Data Engineering & Analytics Infrastructure Topics
Data pipeline design, ETL/ELT processes, streaming architectures, data warehousing infrastructure, analytics platform design, and real-time data processing. Covers event-driven systems, batch and streaming trade-offs, data quality and governance at scale, schema design for analytics, and infrastructure for big data processing. Distinct from Data Science & Analytics (which focuses on statistical analysis and insights) and from Cloud & Infrastructure (platform-focused rather than data-flow focused).
Geospatial and Real Time Processing
Covers design and operation of systems that handle spatial data and low latency event streams. Candidates should explain spatial indexing and query techniques, map matching and coordinate reference considerations, spatial accuracy and privacy trade offs, and storage approaches for geospatial data. For real time processing describe ingestion, messaging patterns, stream processing concepts such as windowing and stateful processing, ordering and delivery semantics, partitioning and scaling strategies, backpressure and fault handling, and trade offs between real time and batch analytics for customer facing metrics.
Analytics Platforms and Dashboards
Comprehensive knowledge of analytics platforms, implementation of tracking, reporting infrastructure, and dashboard design to support marketing, product, and content decisions. Candidates should be able to describe tool selection and configuration for platforms such as Google Analytics Four, Adobe Analytics, Mixpanel, Amplitude, Tableau, and Looker, including the trade offs between vendor solutions, native platform analytics, and custom instrumentation. Core implementation topics include defining measurement plans and event schemas, event instrumentation across web and mobile, tagging strategy and data layer design, Urchin Tracking Module parameter handling and cross domain attribution, conversion measurement, and attribution model design. Analysis and reporting topics include funnel analysis, cohort analysis, retention and segmentation, key performance indicator definition, scheduled reporting and automated reporting pipelines, alerting for data anomalies, and translating raw metrics into stakeholder ready dashboards and narrative visualizations. Integration and governance topics include data quality checks and validation, data governance and ownership, exporting and integrating analytics with data warehouses and business intelligence pipelines, and monitoring instrumentation coverage and regression. The scope also covers channel specific analytics such as search engine optimization tools, social media native analytics, and email marketing metrics including delivery rates, open rates, and click through rates. For junior candidates, demonstration of fluency with one or two tools and basic measurement concepts is sufficient; for senior candidates, expect discussion of architecture, pipeline automation, governance, cross functional collaboration, and how analytics drive experiments and business decisions.
Data Reliability and Fault Tolerance
Design and operate data pipelines and stream processing systems to guarantee correctness, durability, and predictable recovery under partial failures, network partitions, and node crashes. Topics include delivery semantics such as at most once, at least once, and exactly once and the trade offs among latency, throughput, and complexity. Candidates should understand idempotent processing, deduplication techniques using unique identifiers or sequence numbers, transactional and atomic write strategies, and coordinator based or two phase commit approaches when appropriate. State management topics include checkpointing, snapshotting, write ahead logs, consistent snapshots for aggregations and joins, recovery of operator state, and handling out of order events. Operational practices include safe retries, retry and circuit breaker patterns for downstream dependencies, dead letter queues and reconciliation processes, strategies for replay and backfill, runbooks and automation for incident response, and failure mode testing and chaos experiments. Data correctness topics include validation and data quality checks, schema evolution and compatibility strategies, lineage and provenance, and approaches to detect and remediate data corruption and schema drift. Observability topics cover metrics, logs, tracing, alerting for pipeline health and state integrity, and designing alerts and dashboards to detect and diagnose processing errors. The topic also includes reasoning about when exactly once semantics are achievable versus when at least once with compensating actions or idempotent sinks is preferable given operational and performance trade offs.
Data Quality and Edge Case Handling
Practical skills and best practices for recognizing, preventing, and resolving real world data quality problems and edge cases in queries, analyses, and production data pipelines. Core areas include handling missing and null values, empty and single row result sets, duplicate records and deduplication strategies, outliers and distributional assumptions, data type mismatches and inconsistent formatting, canonicalization and normalization of identifiers and addresses, time zone and daylight saving time handling, null propagation in joins, and guarding against division by zero and other runtime anomalies. It also covers merging partial or inconsistent records from multiple sources, attribution and aggregation edge cases, group by and window function corner cases, performance and correctness trade offs at scale, designing robust queries and pipeline validations, implementing sanity checks and test datasets, and documenting data limitations and assumptions. At senior levels this expands to proactively designing automated data quality checks, monitoring and alerting for anomalies, defining remediation workflows, communicating trade offs to stakeholders, and balancing engineering effort against business risk.
Data Quality and System Integration Challenges
Focuses on data integrity, governance, and the operational issues that arise when data moves between systems. Candidates should be able to identify common data quality problems such as duplicates, missing or inconsistent fields, formatting mismatches, schema drift, and validation gaps. Understand how those issues propagate through integration pipelines and impact reporting, analytics, forecasting, and other downstream processes. Discuss reconciliation strategies, validation rules, data cleansing, deduplication, master data management patterns, monitoring and alerting for data anomalies, and policies for schema evolution and versioning. Also cover practical approaches to prevent and remediate integration induced data errors and how to prioritize data quality work across cross-system business workflows (for example, CRM/billing integrations, HR and compensation data feeds, marketing automation pipelines, or product analytics), not just any single business function.
Data Integration and Flow Design
Design how systems exchange synchronize and manage data across a technology stack. Candidates should be able to map data flows from collection through activation, choose between unidirectional and bidirectional integrations, and select real time versus batch synchronization strategies. Coverage includes master data management and source of truth strategies, conflict resolution and reconciliation, integration patterns and technologies such as application programming interfaces webhooks native connectors and extract transform load processes, schema and field mapping, deduplication approaches, idempotency and retry strategies, and how to handle error modes. Operational topics include monitoring and observability for integrations, audit trails and logging for traceability, scaling and latency trade offs, and approaches to reduce integration complexity across multiple systems. Interview focus is on integration patterns connector trade offs data consistency and lineage and operational practices for reliable cross system data flow.
Data Architecture and Pipelines
Designing data storage, integration, and processing architectures. Topics include relational and NoSQL database design, indexing and query optimization, replication and sharding strategies, data warehousing and dimensional modeling, ETL and ELT patterns, batch and streaming ingestion, processing frameworks, feature stores, archival and retention strategies, and trade offs for scale and latency in large data systems.
Cloud Data Architecture and Tradeoffs
Designing data architectures specifically for cloud environments and evaluating platform trade offs. Topics include when to use managed relational services, managed nonrelational services, cloud data warehouses, cloud object storage, lifecycle policies, cross region replication, data residency and compliance considerations, cost versus performance trade offs, managed service operational constraints, and strategies for high availability and disaster recovery in the cloud. Candidates should be able to compare cloud service options and justify choices based on reliability, cost, and compliance.
Data Cleaning and Quality Validation in SQL
Handle NULL values, duplicates, and data type issues within queries. Implement data validation checks (row counts, value distributions, date ranges). Practice identifying and documenting data quality issues that impact analysis reliability.